Systems that allow a call to be forwarded from a called node of a network to another node are well known. If a user who receives service via a first node enables call forwarding to a user site that is serviced by means of a second node, a call to the first node will be diverted to the second node. Thus, there is a call path from the originating node to the first node and a forwarding path from the first node to the second node in order to place a calling user in contact with the called user.
While the call forwarding capability provides a number of conveniences, the prior art approach is susceptible to adding significantly to the costs of certain types of call connections. For example, a call may be originated from a node within the United States, while the called node may be in Germany. This call path will typically require the use of relatively expensive international integrated services digital network (ISDN) facilities, either switched or leased. If the destination node to which the call is to be diverted is also within the United States, an international trunk will again be required for the forwarding path from the called node to the destination node. The double use of the international trunk will significantly increase the cost of the connection call from the originating user to the destination user.
U.S. Pat. No. 5,452,349 to Uehara et al. describes an improvement for use in a communication system that includes a public network connected to an ISDN. A call deflection control system is included within the public network. If call forwarding is enabled at a terminal of the public network, a judgment will take place upon receiving a call from a terminal of the ISDN. The control system judges whether the call is to be forwarded to a terminal of the called public network or to a terminal of the originating ISDN. If the call is to remain within the public network, the forwarding is executed at the terminal of the public network. On the other hand, if the call is to be forwarded to a second terminal of the ISDN, a request is made to the ISDN to execute call forwarding.
This eliminates the problems associated with using two different ISDN lines.
The system of Uehara et al. has advantages over prior art call forwarding control systems. However, application of the system is limited. For example, the destination of the forwarded call may be in a third network, so that the Uehara et al. system is not applicable.
What is needed is a method and system for managing calls to be forwarded such that facilities and resources are conserved.